Aerosol generator

ABSTRACT

An aerosol generator device for delivering an aerosol of a nicotine salt is provided. The aerosol generator comprises: (i) a mouth end; (ii) a first chamber containing a porous material wetted with liquid nicotine, (iii) a second chamber containing a porous material wetted with a solution of a volatile acid, (iv) a third chamber in fluid communication with the first and second chambers, leading to the mouth end, and (v) an outer housing defining a passageway for air through said device. A nicotine vapor can be produced by drawing air along the passageway and through the porous material wetted with liquid nicotine. An acid vapor can be produced by passing air along the passageway and through the porous material wetted with a solution of a volatile acid. Then, the nicotine vapor and the acid vapor can be admixed in the third chamber to form an aerosol of a nicotine salt, which can be drawn out through the mouth end.

FIELD OF INVENTION

The invention relates generally to a nicotine aerosol generator andmethods of manufacturing same, as well as methods for delivering anaerosol of a nicotine salt and methods for assisting a person to stopsmoking and/or providing a substitute for tobacco smoking.

BACKGROUND

As an alternative to smoking cigarettes, certain products have beendeveloped as tobacco-smoking alternatives or substitutes. Such productsinclude, for example, nicotine-containing chewing gum,nicotine-containing nose drops, nicotine skin patches, lozenges, andnicotine sprays. For example, see U.S. Pat. Nos. 4,793,366; 4,813,437;4,920,989; 4,945,929; 4,953,572; 5,656,255; 5,834,011; 5,893,371; and6,024,097.

Often these tobacco-smoking alternatives or substitutes have certaindrawbacks. For instance, these products may not sufficiently simulatethe experience of smoking a cigarette. In particular, the nicotinelevels produced are typically lower than those produced by tobaccosmoking. Also, the absorption of nicotine into the bloodstream is slowerthan with conventional tobacco smoking. Moreover, these substitutemethods sometimes have unpleasant side effects, including nausea,indigestion and throat or mouth irritation.

Accordingly, it is desirable to provide improved alternatives orsubstitutes for tobacco smoking and/or products for delivering nicotineas part of a program to assist smokers to discontinue smokingcigarettes.

SUMMARY

An aerosol generator for delivering an aerosol of a nicotine salt isprovided. In an embodiment, the aerosol generator device for deliveringan aerosol of a nicotine salt, comprises (i) a mouth end; (ii) a firstchamber containing a porous material wetted with liquid nicotine; (iii)a second chamber containing a porous material wetted with a solution ofa volatile acid; (iv) a third chamber in fluid communication with boththe first and second chambers, and leading to the mouth end, and (v) anouter housing defining a passageway for air through said device. Theouter housing preferably contains at least the first and second chamber,and may also contain the third or any additional chambers as well.

A nicotine vapor can be produced by passing or drawing air through theporous material wetted with liquid nicotine. An acid vapor can beproduced by passing or drawing air through the porous material wettedwith a solution of a volatile acid. The nicotine vapor and the acidvapor can be admixed in the third chamber to form an aerosol of anicotine salt, which can be drawn out the mouth end.

The aerosol of the nicotine salt produced is about 0.1 to 10 microns insize, preferably about 0.1 to 3 microns in size.

In an embodiment, the volatile acid in the second chamber is selectedfrom the group consisting of hydrochloric acid, phosphoric acid, aceticacid and sulphuric acid.

In another embodiment, the form of the liquid nicotine is (i) a racemicmixture, (ii) an unequal amount of the D and L isomers of nicotine,(iii) substantially the D isomer of nicotine or (iv) substantially the Lisomer of nicotine. Preferably, the form of the nicotine issubstantially the L isomer.

If desired, either the first chamber or the second chamber furthercomprise at least one additive selected from the group consisting of aviscosity agent, an antioxidant or a preservative. Optionally, theaerosol generator may further comprise a fourth chamber, wherein thefourth chamber contains at least one additive selected from the groupconsisting of water, alcohol and flavoring. In another embodiment, theaerosol generator may optionally further comprise in the mouth end, asufficient amount of a basic compound to remove any excess acid vapor,for example, calcium carbonate can be used to remove acid vapor from theaerosol. Examples of flavoring that may be incorporated into the aerosolgenerator include menthol, for example.

In one embodiment, an aerosol generator contains a total of about 1-50mg of nicotine, preferably about 1-20 mg of nicotine per device. Forexample, the aerosol generator can dispense about 0.5 to 20 mg ofnicotine to the user, preferably about 0.5 to 10 mg of nicotine to theuser. The aerosol generator can include a 10 mg nicotine capsule todeliver about 4 mg of nicotine to the user. In general, the aerosolgenerator delivers an inhalation volume of about 10 to 1000 cc per drawor puff, preferably an inhalation volume of about 35 to 350 cc per drawor puff. In certain embodiments, the person would use about 5-20cartridges a day, but this number can vary depending upon the personalpreference of the user.

In yet another embodiment, a method for assisting in the reduction ofthe desire of a subject to smoke tobacco and/or providing to a smoker asubstitute for tobacco smoking is provided. Such methods comprise usingan aerosol generator as described herein to deliver an aerosol of anicotine salt to a subject.

DETAILED DESCRIPTION

The invention relates generally to an aerosol generator for deliveringan aerosol of a nicotine salt.

In one embodiment, the aerosol generator comprises: (i) a mouth end;(ii) a first chamber containing a porous material wetted with liquidnicotine, (iii) a second chamber containing a porous material wettedwith a solution of a volatile acid, and (iv) a third chamber in fluidcommunication with both the first and second chambers, and leading tothe mouth end.

A nicotine vapor can be produced by passing air through the porousmaterial wetted with liquid nicotine. The nicotine is vaporized as aresult of its vapor pressure. An acid vapor can be produced by passingair through the porous material wetted with a solution of a volatileacid. Then, the nicotine vapor and the acid vapor can be contacted inthe third chamber as the user draws them up through the device byinhaling from the mouth end.

While not wishing to be limited by theory, it is believed thatcontacting the two vapor-laden streams allows the nicotine to contactthe acid in the vapor phase, causing an acid-base reaction between thebasic nicotine molecule, and the acid to form a nicotine salt. Thenicotine salt has low volatility, and forms an aerosol, which can bedrawn out the mouth end.

Advantages of the aerosol device over other aerosol generators includethe simplicity of design and operation, and the small aerosol particlesize generated. Also, the aerosol generator as described hereinadvantageously does not require any excipients or aerosol carrier. Inaddition, the aerosol generator does not pose a fire risk, and also doesnot produce second-hand or sidestream smoke. Advantageously, the aerosolof the nicotine salt is delivered substantially free of tar, and alsofree of mainstream smoke.

The aerosol generator in one embodiment is in the shape of a tube with amouth end. The mouth end may optionally contain a filter type materialif desired. The user is able to draw air through the tube from the mouthend, such that the air is passed through both the first chamber andsecond chamber.

Optionally, in a preferred embodiment, the mouth end can further containa suitable material to absorb any solid and/or excess acid vapor. Oftena basic compound is used for this purpose, such as a carbonate.Preferably, calcium carbonate may be used for this purpose.

In an embodiment, the aerosol generator is in the shape of a tube, whichis about 1-15 cm long and 5-10 mm in diameter. Preferably, the aerosolgenerator is about 7-8 cm long and about 7 mm in diameter. In oneembodiment, the aerosol generator may be in the form of adouble-barreled tube, with the third chamber at the mouth end of thetube.

In a preferred embodiment, the aerosol generator will have theappearance and be about the same size as a cigarette. In this regard, aregular cigarette is about 70 to 120 mm long, preferably about 85 mm,and the circumference is from about 15 mm to about 30 mm incircumference, preferably about 25 mm.

Nicotine is extracted from tobacco in the form of a water-soluble,alkaline, oily liquid. The chemical structure of nicotine is as follows:

As illustrated above, nicotine is a tertiary amine comprising a pyridineand a pyrrolidine ring. It is colorless to pale yellow in color, andturns brown on exposure to air or light. Nicotine is also a volatile,hygroscopic liquid. Accordingly, to extend the shelf life in acommercial embodiment, it may be desirable that the aerosol generator bewrapped in foil or a sealed packaging material, to minimize the exposureto air and light. Prior to use, the user can conveniently remove thepackaging material.

The liquid nicotine used in the aerosol generator may be in the form of(i) a racemic mixture, (ii) an unequal amount of the D and L isomers,(iii) substantially the D isomer or (iv) substantially the L isomer. By“substantially” is meant that a specific enantiomer will contain lessthan 10%, e.g. less than 5% and advantageously less than 1%, e.g., lessthan 0.5% of its opposite enantiomer. Preferably, the L-isomer is used(which corresponds to the S-isomer when using the Cahn-Ingold-Prelognomenclature system).

The term “liquid nicotine” includes both nicotine in the liquid or oilform, as well as nicotine in the form of a solution. In a preferredembodiment, a physiologically acceptable solution is used, for example,including but not limited to, water, saline or phosphate-bufferedsaline.

The nicotine is placed on a suitable porous material. Preferably, theporous material is inert. Examples of porous materials that may be usedinclude, but are not limited to various fibers and polymer materials.The outer housing for the aerosol generator is constructed from asuitable material, such as a plastic or various suitable papermaterials.

It is to be understood that the aerosol generated comprises a gaseoussuspension of fine solids or liquid particles. The mass mean aerodynamicdiameter (MMAD) of these particles is typically from about 0.1-10microns. In contrast, a vapor is the gaseous state of a substance thatis normally a liquid or solid under standard temperature and pressure.It is noted that a vapor in gaseous form is typically exposed to themouth of the user, while an aerosol in particulate form can be exposedto the lungs of the user. Inhaling an aerosol also mimics the sensationof inhaling smoke from a standard cigarette better than a vapor.

Any suitable acid may be used in the second chamber. By “suitable acid,”it is understood that the acid must be selected such that it is volatileenough to be admixed with the nicotine vapor, and such that it is strongenough to react with the nicotine. In addition, the acid should beselected such that it is physiologically acceptable. Examples ofsuitable acids include, but are not limited to, acetic acid and possiblyhydrochloric acid, phosphoric acid, sulphuric acid, and mixturesthereof.

As mentioned above, the size of the aerosol particles is sufficient tosimulate the sensation normally achieved by tobacco smoke. For example,the MMAD of the aerosol particles is typically between about 0.1-10microns, preferably 0.1-3 microns.

In a further embodiment, the aerosol generator may also further comprisea fourth chamber, wherein the fourth chamber contains at least oneadditive selected from the group consisting of water, alcohol andflavoring. Any suitable flavoring agent may be used, such as but notlimited to menthol.

The materials in each of the chambers may additionally contain suitableamounts of other additives such as, but not limited to standardviscosity agents (e.g., cellulose or substituted cellulose such ascarboxymethyl cellulose, lanolin, beeswax, gum arabic, PEG),preservatives (e.g., benzoic acid) and/or antioxidants (e.g., ascorbicacid).

In yet another embodiment, a method for assisting a person to quitsmoking is provided, which comprises delivering an aerosol of a nicotinesalt, wherein the aerosol of the nicotine salt is of such particle sizeand quantity to provide comparable or reduced uptake of nicotine ascompared to tobacco smoking. In an embodiment, suitable levels ofnicotine may be used, for example, levels suitable for use in a methodfor assisting in the reduction of the desire of a subject to smoketobacco and/or for providing to a smoker a substitute for tobaccosmoking.

While the invention has been described with reference to preferredembodiments, it is to be understood that variations and modificationsmay be resorted to as will be apparent to those skilled in the art. Suchvariations and modifications are to be considered within the purview andscope of the invention as defined by the claims appended hereto.

All of the above-mentioned references are herein incorporated byreference in their entirety to the same extent as if each individualreference was specifically and individually indicated to be incorporatedherein by reference in its entirety.

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 15. (canceled)16. A method for assisting in the reduction of the desire of a subjectto smoke tobacco or providing to a subject a substitute for tobaccosmoking, which method comprises delivering to said subject an aerosol ofa nicotine salt produced by the following steps: producing a nicotinevapor by passing air through a porous material wetted with liquidnicotine; producing an acid vapor by passing air through a porousmaterial wetted with a solution of a volatile acid, and admixing thenicotine vapor and the acid vapor to form the aerosol of a nicotinesalt.
 17. A method of claim 16, where the nicotine aerosol is generatedby an aerosol generator which delivers about 0.5 to 20 mg of nicotine.18. A method of claim 17, where the aerosol generator delivers about 0.5to 10 mg of total nicotine.
 19. A method of claim 17, where the aerosolgenerator delivers an inhalation volume of about 10 to 1000 cc per puffor draw.
 20. A method of claim 17, where the aerosol generator deliversan inhalation volume of about 35 to 350 cc per puff or draw.
 21. Amethod of making an aerosol generator device for delivering an aerosolof a nicotine salt, comprising: (i) combining a first chamber containinga porous material wetted with liquid nicotine, a second chambercontaining a porous material wetted with a solution of a volatile acid,and a third chamber in fluid communication with the first and secondchambers and leading to a mouth end, wherein a nicotine vapor can beproduced by passing air through the porous material wetted with liquidnicotine, wherein an acid vapor can be produced by passing air throughthe porous material wetted with a solution of a volatile acid, andwherein the nicotine vapor and the acid vapor can be admixed in thethird chamber to form an aerosol of a nicotine salt, which can be drawnout the mouth end; and (ii) surrounding the device with an outer housingthat defines a passageway for air through said device to form theaerosol generator device.
 22. A method of using an aerosol generatordevice for delivering an aerosol of a nicotine salt, comprising: flowingor drawing air through an aerosol generator device comprising a mouthend; a first chamber containing a porous material wetted with liquidnicotine; a second chamber containing a porous material wetted with asolution of a volatile acid; a third chamber in fluid communication withthe first and second chambers, and leading to the mouth end, and anouter housing defining a passageway for the air through said device,producing nicotine vapor by passing at least some of the air through theporous material wetted with liquid nicotine, producing acid vapor bypassing at least some of the air through the porous material wetted witha solution of a volatile acid, and admixing the nicotine vapor and theacid vapor in the third chamber to form an aerosol of a nicotine salt,which is drawn out the mouth end.
 23. A method of producing an aerosolof nicotine salts, comprising: producing a nicotine vapor by passing airthrough a porous material wetted with liquid nicotine; producing an acidvapor by passing air through a porous material wetted with a solution ofa volatile acid, and admixing the nicotine vapor and the acid vapor toform the aerosol of a nicotine salt.
 24. A method of producing anaerosol of nicotine salts, comprising: producing a nicotine vapor bypassing air through a porous material wetted with liquid nicotine;producing an acid vapor by passing air through a porous material wettedwith a solution of a volatile acid, admixing the nicotine vapor and theacid vapor to form the aerosol of a nicotine salt, and contacting theaerosol with a basic compound in an amount effective to remove acidvapor in the aerosol.
 25. A method of claim 24, wherein the basiccompound is calcium carbonate.